A portable terminal can make a call using a variety of media (hereinafter called ‘call media’), such as a microphone installed thereto, a microphone connected to earphones, a microphone connected to a Bluetooth® headset, and the like. For example, a portable terminal transmits a user's voice signal to the other portable terminal and also receives the other user's voice signal via the media, such as a receiver, earphones, a loud speaker, a Bluetooth® headset, and the like, There from. When the portable terminal communicates with the other portable terminal, voice call quality is a very important factor.
Portable terminals communicate through a variety of communication methods, such as RF communication, wired communication, Internet Protocol (IP) communication, and the like.
A portable terminal, which can support a dual mode/dual standby mode or more modes, uses a SIM card of at least one network (service provider). For example, a single portable terminal can be operated through a plurality of networks (service providers).
When portable terminals make a call, their voice call qualities differ according to a variety of call media, communication methods, and networks (service providers).
Conventional portable terminals fix their values for setting voice call quality, such as voice quality, volume, and the like, to a default value. For example, the terminals cannot adaptively change their values according to a variety of call media, communication methods, and networks (service providers). Therefore, they cannot provide optimal voice call quality according to a variety of call media, communication methods, and networks (service providers).